This article does a good job of using and explaining diary studies, an intriguing data collection method that has its advantages and disadvantages. One advantage is that participants have control over the data collection and what and how they choose to code can be as instructive as the data itself. The result is that participants choose their own scale and definition for tasks, events, and details.

Most intriguingly, the authors provide a prototype application for helping participants switch tasks.

Czerwinski and her colleagues have used other methods as well. In this article, they use Vibelog to log system events in order to get a sense of how participants used screen real estate. They demonstrate through several intriguing visualizations that the larger the screen real estate, the more productive the participant tends to be and the more likely s/he is to recover from interruptions. Of course, logging system events has the opposite problem from diary studies: you get a precise idea of what happens on screen, but not much insight into what's happening offscreen.

In this article, Bradner and Mark are interested in how perceptions of distance affects interactions. They investigate with a straight-ahead experiment: a participant sits in a room with a terminal and interacts cooperatively (via either webcam or IM) to solve problems with someone at a distance. The participant is told that the participant is either in the same city or across the country. The greater the perceived distance, the less cooperatively the participant tended to interact.

Here, the investigators turn to shadowing as a data collection method. In their in situ study of 14 information workers over a seven-month period, they concluded that people organize work in large, thematically connected units that they call "working spheres." Workers switch among an average of ten working spheres.

The term brings to mind other units of analysis, such as activity systems. But Gonzalez and Mark mean ways in which people divide their work (ex: central, peripheral, personal) rather than stable cyclical object-oriented activities:

We define a working sphere as a set of interrelated events, which share a common motive (or goal), involves the communication or interaction with a particular constellation of people, uses unique resources and has its own time framework. With respect to tools, each working sphere might use different documents, reference materials, software, or hardware. It is the whole web of motives, people, resources, and tools that distinguishes it from other working spheres. (p.117)

Notice that the working sphere is primarily defined by the material and human concatenation rather than the orientation toward a particular goal -?although "motives" is slipped in there. This sounds much more like distributed cognition's functional units than, say, activity theory's activity systems. And without that strong object-orientation, it seems likely that the unit is going to have trouble being nailed down or explained. On the other hand, downplaying the motive gives the working sphere the same advantages as actor-networks, ontologically speaking.

The authors also note that many artifacts both signal and describe work: post-it notes, planners, printouts, and email inboxes. Finally, they provide a nice succinct definition of work fragmentation based on the appropriate literature (p.119). They found that workers tended to switch between working spheres about every three minutes.

This article appears to be describing the same study as the one above. The authors argue that there are two components to work fragmentation: (a) time spent in the activity and (b) frequency of interruptions.

We define work fragmentation as a break in continuous work activity. Studies continually describe how the work of information workers is characterized by spending short amounts of time in tasks and switching frequently. This has been found with managers [7,13,23], financial analysts [6], software developers [18], and even telecommuters [8]. Studies have also reported on the interruptions that information workers experience [4,7,16,20]. (p.321)

They invoke the literature on work fragmentation more thoroughly here, and argue that "managing multiple activities is becoming more recognized as a basic characteristic of work life for information workers" (p.321).

Mark, G. and Poltrock, S. (2003). Shaping technology across social worlds: groupware adoption in a distributed organization. In GROUP ?03: Proceedings of the 2003 international ACM SIGGROUP conference on Supporting group work, pages 284?293, New York, NY, USA. ACM Press.

The authors are here concerned about spatial and temporal distribution of work, particularly in distributed organizations:

Distributed organizations can be considered to be fluid organizations. The boundaries between work units may be in continual flux as teams reconfigure to incorporate expertise drawn from any geographical location in the company. Distributed organizations do not have one adoption context, but many, depending on for example, whether people are working with colleagues who are collocated or remote. Thus, various contexts and group configurations are involved in adoption decisions. We propose social world theory as a framework for understanding technology diffusion across distance in a distributed organization. (p.285)

They see social world theory as a complement to working spheres. My inclination is to subsume both in terms of activity systems and networks: it would allow them to get to the main idea of a social world as a unit of collective action, describe multiple adoption contexts (p.285), and describe action as fluid, diverse, and multiple (pp.285-286). Nevertheless, the piece is really valuable for thinking about how human activity is changed by distributed work.